The present invention relates to a closed cheese making vat including means for cutting and agitating the curds formed in the vat during the cheese making process. Such vats are shown by way of example in the patent to Hazen, U.S. Pat. No. 3,858,855, issued Jan. 7, 1975. Such apparatus generally comprise a vat for receiving milk along with various additives which will cause the milk to curdle. The vats include means for heating and stirring the milk and additives until curds are formed and means to cut the curds into small pieces to facilitate separation of the curds and whey. During a cheese making process using this type of apparatus, following the cutting step, the curds are allowed to precipitate out of the whey so that a portion of the whey can be drawn off. It is then necessary to agitate the remaining whey and curd slurry until the completion of the process when the slurry may be removed from the tank for further processing.
Some of the prior art apparatus, such as that shown in the patent to Hazen have sought to provide a single means for performing both the cutting operation and the agitating operation. Using a single means for cutting and agitating is advantageous, however, such prior art apparatus have been unduly complicated. For example, in the apparatus disclosed in the Hazen patent the cutting and agitating means shown therein require a drive mechanism which will first rotate the cutting and agitating means in one direction to perform the curd cutting operation and then rotate them in the opposite direction for agitating the curd and whey solution or slurry. Such prior art apparatus also show the cutting and agitating means as having hinged or pivotable parts which were immersible in the curd and whey solution. After each use of the vats it is necessary to spray the vats with a cleaning solution to remove any residue left in the vat which could contaminate the subsequent batch. The use of the hinged or pivotable parts has the disadvantage that the pivot joints can collect residue and substantially increase the difficulty involved in cleaning the apparatus.